The present invention relates to a device for holding precious stones during cutting and polishing the facets thereof.
Precious stones are usually mounted to a holder, sometimes called a "Dop", during the cutting and polishing of their facets, the holder being held by hand while the stone is pressed against a rotatary-driven cutting or polishing disc. One common form of hand-held holder includes a rod having a mounting tip at one end of mounting the stone to be polished, and a positioning collar fixed to the rod adjacent to the mounting tip, the positioning collar having an outer polygonal (e.g. octagonal) configuration for positioning the stone in different angular positions with respect to the cutting or polishing disc. Such an arrangement, however, enables only a limited number of facets to be conveniently cut and polished because of the limited number of flat surfaces provided by the polygonal configuration of the positioning collar.
Another device commonly used includes a holding fixture which receives the rod to which the stone is mounted, the holding fixture including a clamping arrangement for receiving and securely clamping the rod thereto. Such holding fixture, however, is of a relatively complicated and costly construction and therefore one such fixture is usually used with a series of rods. The usual procedure is to apply a series of rods, one after the other, to the fixture for first cutting the facets in the stones carried by the series of rods, and then to reintroduce the rods again one after the other for polishing the cut facets. This produces an alignment problem in aligning the rod, when inserted for the subsequent polishing operation, exactly in the same position it was in the fixture during the facet cutting operation.
An object of the present invention is to provide a device for holding precious stones during the cutting and polishing of thier facets which device has advantages in both of the above respects.
More particularly, an object of the present invention is to provide a device for holding a precious stone to enable a large number of different facets to be cut and polished, which device is of simple and inexpensive construction such as to permit it to be retained attached to the stone during both the cutting and the polishing operation thereby obivating the alignment problems mentioned above.